1. Field of the Invention
This invention relates, generally, to means for connecting to trucks or similar vehicles flexible substrates upon which advertising messages may be printed. More particularly, it relates to an apparatus for connecting such a substrate in overlying relation to the rear wall of a truck having an overhead-opening door and to an apparatus for tightening the respective leading ends of opposing, side wall-covering substrates when only a narrow space is available.
2. Description of the Prior Art
The present inventor has provided heretofore a substrate adapted to be secured to the side walls of a truck. He has also provided a means for securing such a substrate to the back wall of a truck of the type having doors that swing open about a vertical hinge.
However, a mounting means for securing a substrate to a back wall of a truck or trailer of the type having an overhead-opening door has not heretofore been disclosed.
As used herein, the term "truck or trailer" refers to trucks of all types, including full trailers (where all of the weight is borne by a single chassis) and semi-trailers (where the weight is shared between the tractor chassis and the trailer chassis). It includes those vehicles where the cargo-receiving part is just a few inches behind the cab or tractor and it further includes those vehicles where the cargo-receiving part thereof is spaced a foot or more from the tractor or cab, as in most semi-trailers.
Doors of the overhead type are formed by a collection of panels that are hingedly connected to one another by vertically spaced apart horizontally-extending hinges. When an overhead door is opened, its panels ride in a curved track until all panels are in a horizontal disposition near the top of the truck or trailer when the door is fully open. The distance between the top edge of the uppermost panel and the lower edge of the lowermost panel is greater when the door is open than when the door is closed. As a result, if a substrate is tightly secured in overlying relation to such a door when the door is closed, the substrate must stretch several inches along its height when the door is opened. Thus, after such a stretching has taken place, the substrate will be loose when the door is closed if the substrate is not perfectly elastic, i.e., if the substrate lacks sufficient resilience to return to its pre-stretched state.
However, durable material of the type suitable for use as a substrate upon which high quality advertising messages may be imprinted is substantially nonstretchable. Accordingly, alternate means must be found that will allow such a substrate to be used with an overhead door. Such means should not require stretching of the substrate.
More specifically, there is a need for an assembly of parts that tightly secures a substantially nonstretchable substrate in overlying relation to a truck or trailer door of the overhead-opening type, and which allows the door to be opened and closed without requiring the substrate to stretch when the door is opened or contract when the door is closed.
Another problem is extent in the field of trucks or trailers where the cab occupied by the driver is positioned closely to the cargo-receiving part of the truck or trailer. In those trucks or trailers where there is ample space between the forward or front wall of the cargo-receiving part of the truck or trailer and the back wall of the cab, relatively large winches or equivalent devices may be employed to draw together the respective forward edges of the substrates that overlie the respective side walls of the cargo-receiving part of the truck or trailer because the clearance space between the cab and the cargo-receiving part is usually several feet; a person can stand in front of the winches and operate them without physical space restrictions. Such winches cannot be mounted or easily accessed, however, when advertising messages are imprinted upon substrates that are attached to the side walls of trucks or trailers having limited space, such as just a few inches, between the cab and the front wall of the cargo-receiving part of the truck or trailer.
Thus there is a need for a means for tightening the respective forward edges of substrates that overlie the side walls of a truck or trailer of the type having little clearance between the cab and the cargo-receiving part thereof. The tightening means should be easily operable even in the very small space between a cab back wall and the front wall of the cargo-receiving part of the truck or trailer.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in this art how the needed improvements could be provided.